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Functional Description
2.2 Mechanical Design of the AKE 200
For parameters, see chapter
!
DANGER
The entire capacitive wattless current of the coupling capacitor flows to ground via the drain coil.
Connecting cables in the vicinity of the drain coil for individual operating scenarios should be installed
²
with the utmost care.
Isolating Capacitor
2.2.5
Since the 50-Hz wattless current at the impedance of the drain coil can still produce a voltage drop of several
volts the isolating capacitor is required to prevent an excessively high magnetic flux in the isolation trans-
former with the mains frequency. The capacitance is small enough to block the 50 Hz current from the isola-
tion transformer and provides a low impedance for the RF signal to be transmitted undistorted.
2.2.6
Isolation Transformer
The isolation transformer is the most important component of the AKE. It provides safe isolation between the
high-voltage side and the PLC equipment side and matches the impedance between highvoltage line and CF
cable as required. A special potting technique prevents any hazard to the secondary side even if the primary
side fails in the unlikely event of mechanical destruction due to high voltage influence.
For parameters, see chapter
Secondary Surge Arrester
2.2.7
The secondary surge arrester shorts out interference voltages that do not cause the primary voltage arrester to
respond. These interference voltages can arise both from the line as steep voltage pulses and from a carrierfre-
quency cable exposed to high-voltage interference.
The secondary surge arresters are designed firstly to limit dangerous surge voltages and secondly to prevent
corona discharge of the gas-filled surge arresters due to the HF voltage.
In order to ensure that the arrester is extinguished again after ignition by a peak transient the peak value of
the carrier frequency operating voltage must remain below the corona potential of the series-connected
gasfilled arresters at this point.
HF Hybrid Transformer AKE 200 A1, AKE 200 A4
2.2.8
When connecting two phase-to-ground AKEs to a PLC device, e.g. in an inter-system coupling, an HF hybrid
transformer is generally used as shown in the application example in Fig. 3. It should have an adequately large
cross section to decouple both coupling phases and a low throughput loss.
Due to the hybrid principle it is possible to maintain a PLC link over half the transmission path if the other line
path is out of action, e.g. as a result of short circuit, ground fault or total failure.
The HF hybrid transformer is suitable for the application of either balanced 150 Ω cables or unbalanced 75 Ω
cables. It can be located in a separate case (AKE 200 A1), if possible equidistant between the two phase-to-
ground AKEs, or installed directly in one of the two coupling units if they are less that 30m apart.
Basic circuit diagrams:
18
5 Technical Data
5 Technical Data
Smart Communication, AKE 200 Coupling Unit, Manual
C53000-G6540-C265-2, Edition 11.2020
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